The Collaborative International Dictionary of English v.0.48:

Encomiast \En*co"mi*ast\, n. [Gr. ?, fr. ? to praise, fr. ?
   encomium: cf. F. encomiaste. See Encomium.]
   One who praises; a panegyrist. --Locke. Encomiastic

The Devil's Dictionary (1881-1906):

ENCOMIAST, n.  A special (but not particular) kind of liar.